# Ultralytics 🚀 AGPL-3.0 License - https://ultralytics.com/license

import numpy as np

from ultralytics.solutions.solutions import BaseSolution, SolutionAnnotator, SolutionResults
from ultralytics.utils.plotting import colors


class RegionCounter(BaseSolution):
    """
    A class for real-time counting of objects within user-defined regions in a video stream.

    This class inherits from `BaseSolution` and provides functionality to define polygonal regions in a video frame,
    track objects, and count those objects that pass through each defined region. Useful for applications requiring
    counting in specified areas, such as monitoring zones or segmented sections.

    Attributes:
        region_template (dict): Template for creating new counting regions with default attributes including name,
            polygon coordinates, and display colors.
        counting_regions (list): List storing all defined regions, where each entry is based on `region_template`
            and includes specific region settings like name, coordinates, and color.
        region_counts (dict): Dictionary storing the count of objects for each named region.

    Methods:
        add_region: Adds a new counting region with specified attributes.
        process: Processes video frames to count objects in each region.
    """

    def __init__(self, **kwargs):
        """Initializes the RegionCounter class for real-time counting in different regions of video streams."""
        super().__init__(**kwargs)
        self.region_template = {
            "name": "Default Region",
            "polygon": None,
            "counts": 0,
            "dragging": False,
            "region_color": (255, 255, 255),
            "text_color": (0, 0, 0),
        }
        self.region_counts = {}
        self.counting_regions = []

    def add_region(self, name, polygon_points, region_color, text_color):
        """
        Add a new region to the counting list based on the provided template with specific attributes.

        Args:
            name (str): Name assigned to the new region.
            polygon_points (List[Tuple]): List of (x, y) coordinates defining the region's polygon.
            region_color (tuple): BGR color for region visualization.
            text_color (tuple): BGR color for the text within the region.
        """
        region = self.region_template.copy()
        region.update(
            {
                "name": name,
                "polygon": self.Polygon(polygon_points),
                "region_color": region_color,
                "text_color": text_color,
            }
        )
        self.counting_regions.append(region)

    def process(self, im0):
        """
        Process the input frame to detect and count objects within each defined region.

        Args:
            im0 (np.ndarray): Input image frame where objects and regions are annotated.

        Returns:
            (SolutionResults): Contains processed image `plot_im`, 'total_tracks' (int, total number of tracked objects),
                and 'region_counts' (dict, counts of objects per region).
        """
        self.extract_tracks(im0)
        annotator = SolutionAnnotator(im0, line_width=self.line_width)

        # Ensure self.region is initialized and structured as a dictionary
        if not isinstance(self.region, dict):
            self.region = {"Region#01": self.region or self.initialize_region()}

        # Draw only valid regions
        for idx, (region_name, reg_pts) in enumerate(self.region.items(), start=1):
            color = colors(idx, True)
            annotator.draw_region(reg_pts, color, self.line_width * 2)
            self.add_region(region_name, reg_pts, color, annotator.get_txt_color())

        # Prepare regions for containment check (only process valid ones)
        for region in self.counting_regions:
            if "prepared_polygon" not in region:
                region["prepared_polygon"] = self.prep(region["polygon"])

        # Convert bounding boxes to NumPy array for center points
        boxes_np = np.array([((box[0] + box[2]) / 2, (box[1] + box[3]) / 2) for box in self.boxes], dtype=np.float32)
        points = [self.Point(pt) for pt in boxes_np]  # Convert centers to Point objects

        # Process bounding boxes & check containment
        if points:
            for point, cls, track_id, box, conf in zip(points, self.clss, self.track_ids, self.boxes, self.confs):
                annotator.box_label(box, label=self.adjust_box_label(cls, conf, track_id), color=colors(track_id, True))

                for region in self.counting_regions:
                    if region["prepared_polygon"].contains(point):
                        region["counts"] += 1
                        self.region_counts[region["name"]] = region["counts"]

        # Display region counts
        for region in self.counting_regions:
            annotator.text_label(
                region["polygon"].bounds,
                label=str(region["counts"]),
                color=region["region_color"],
                txt_color=region["text_color"],
                margin=self.line_width * 4,
            )
            region["counts"] = 0  # Reset for next frame
        plot_im = annotator.result()
        self.display_output(plot_im)

        return SolutionResults(plot_im=plot_im, total_tracks=len(self.track_ids), region_counts=self.region_counts)